Nowadays, teachers are facing increasing demands in their work: dealing with diverse groups, supporting the learning process, taking into account the student's needs, interacting with students'parents…etc. These challenges require student teachers to be prepared for real professional contexts of their profession. As a result, it is particularly important for teacher educators to implement assessment strategies that enable their students to acquire some core competences to face the teaching profession world realities and interact with their colleagues. This book surveys the assessment tasks teacher educators assign in cooperative learning groups. It explores their perceptions of an authentic assessment task and how they evaluate its degree of authenticity. Teacher educators’ assessment practices are analyzed according to Gulikers’s five-dimensional framework of an authentic assessment task: the task, the social context, the physical context, the assessment result, the criteria and standards. This analysis should help professionals of Education to reflect on their own practices and question the reliability of group works in Teacher Education.